A 2-Step Ejection Screw Cap

PP, 2-step ejection screw cap, pin gate hot runner, cycle time short to 16 seconds with regular hydraulic injeciton machine.

Item and Finish Target
1Resin & ColorPP-H, Solid Red
2Finish RequirementFull and uniform filling, dimensions meet specifications, good surface without scratches
3Finish Weight16grams/piece
Mold Scenario
4Structure6-cavity, pin gate gate hot runner, sleeve and stripper plate ejection
5Steel & ProcessS50C standard mold base, 2738 core and cavity, quenching & nitriding treatment
Molding
6Machine Clamping force200KN
Cycle Time16 seconds

Why One-Time Ejection is Not Always Sufficient

2-step ejection screw cap

One-time ejection might not be sufficient in certain circumstances due to the following reasons:

  1. Complex Geometries:
    • Parts with intricate designs, undercuts, or fine details might get damaged or deformed if ejected too forcefully in a single step.
  2. Material Properties:
    • Certain materials, such as those with higher adhesion properties or those prone to warping, might stick to the mold surfaces. A single ejection could cause these parts to warp or tear.
  3. Tight Tolerances:
    • For parts with tight dimensional tolerances, a more controlled ejection process helps to maintain the integrity and precision of the dimensions.
  4. Risk of Sticking:
    • Parts that tend to stick to the mold require a gradual release to avoid pulling or tearing. Two-step ejection helps in gently dislodging the part without causing surface defects.
  5. Ejector Pin Marks:
    • A single, forceful ejection can leave marks or indentations from the ejector pins on the part. A two-step process helps to minimize these marks by distributing the force more evenly.
  6. Large or Heavy Parts:
    • Larger or heavier parts benefit from a gradual ejection process to prevent bending or breaking under their own weight during removal.

Example Scenarios

  1. Thin-Walled Parts:
    • Thin-walled plastic parts are prone to deformation if ejected too quickly. A two-step ejection helps to gradually release these parts, maintaining their shape and structural integrity.
  2. Parts with Undercuts:
    • Parts with internal or external undercuts require careful ejection to avoid damage. The initial ejection step helps to release these features gently.
  3. Aesthetic Surfaces:
    • For parts where surface finish is critical, a two-step ejection minimizes the risk of surface defects such as drag marks or scratches.

In summary, the two-step ejection process is particularly useful for handling complex, delicate, or precision parts where a single ejection could lead to defects or damage. By gradually releasing the part from the mold, the process helps ensure higher quality and consistency in the final product.

VolksMolds is a leading plastic injection mold manufacturer known for its expertise, experience, and proven history. The company excels in producing high-precision molds for various sectors, including packaging, store displays, and homewares. With a commitment to quality and innovation, VolksMolds consistently delivers reliable and efficient molds, earning a strong reputation in the global market.